The use of drones in the construction of Crossrail

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In recent years, the use of unmanned aerial vehicles (UAVs) – also known as drones – has grown rapidly across industry and society. Previously only used by the military, we now see them providing footage at sporting events and concerts, and for films and advertisements. They are used in agriculture to monitor crops and animal herds, and in search and rescue for locating missing people. Many sectors have identified ways to improve their working practices through drone use.

Crossrail's innovation programme, Innovate18, hopes to raise the bar in the industry by creating a collaborative culture and bringing in new innovative processes and technology. Innovate18 aims to enhance cooperation between Crossrail's many different contractors, whose common objective is not only the successful delivery a world-class railway, but one delivered safely, efficiently and sustainably.

One of Innovate18's projects is around the use of drones in a construction environment, exploring how they can support field engineers performing site inspections, especially through automating surveys on large sites and on sites with restricted access.

A 'drone team' was put together consisting of media, field engineering, innovation and health and safety professionals. All team members were trained to Civil Aviation Authority (CAA) standards for operating UAVs safely and an operations manual and a safe method of working were created.

Site inspections – close examination of high-risk areas, and speedy overviews of large sites, freeing up time for other tasks.

Health and sfety Induction – site plans can be quickly and efficiently updated to show where different works are taking place (such as lifts and excavations), ensuring that operatives stay safe.

Crane, tower and scaffoldinginspections – a much easier method of inspecting high structures, providing real-time footage to spot anomalies. This reduces site downtime and mitigates risks of personnel having to work at height.

Site planning – overviews can be obtained quickly to inform planning sessions.

360° panoramas – a more immersive experience to enhance appreciation of potential hazards and site orientation.

Site teams identified other potential uses to be trialled and measured:

Logistics planning - many sites are large and change rapidly over a short period. Drones can be used to provide dynamic visualisation, flagging up potential impacts and issues that might otherwise be overlooked, for example, large plant movement and arrangements.

Live feeds - these can be beamed directly to a control room for inspection requirements such as crane clearance, logistics and personnel movement, allowing for real-time decision making, saving time from errors, reducing previously-unidentified risks, and improving quality by aiding the decision-making process.

There is a lot more scope to investigate as UAV technology is constantly changing. The model of the drone used by Innovate18 is a DJI Inspire 1 which receives regular firmware updates to unlock new features, such as waypoint route flying, 3D modelling, and automatic panorama creation – with many more to come.

The drone team meets regularly to practice skills and investigate possible future uses, such as:

Point cloud scanning capabilities which could feed into the BIM model.

Volumetric measurements of items on site, such as excavated materials, supporting logistical planning for removal.

Thermal imaging scanning - investigating opportunities to monitor the health of concrete works safely, any hot spots in electrical sub-stations, and so on.

Waypoint flying - allowing the UAV to fly the same path to create time lapse opportunities and comparative analysis.